This invention relates to machines for forming bales (particularly the type having a rectangular cross section) and more particularly to an improved nozzle array for an applicator assembly. The invention herein has particular utility for the application of preservatives which have a high volitilty (e.g., ammonia).
The potential benefits of applying preservatives to hay, either during a baling process or as a finished bale are well known and include (a) permitting the hay to be baled and stored at higher moisture contents without spoilage, thus reducing field losses (especially losses of leaves in some crops) and making the hay harvesting operation less dependent on favorable weather conditions; (b) improved palatability and digestability; and (c) higher nutrient content. The relative importance of these benefits vary with the crop being treated and the preservative used.
Some of the problems encountered in the application of an ammonia preservative to hay during baling are (a) loss of the ammonia as a vapor; (b) nonuniform distribution throughout the hay; and (c) insufficient retention of the ammonia in the hay to kill the mold organisms.
As disclosed in U.S. Pat. No. 4,185,549, it is known to provide a rectangular baler with a plurality of nozzles for injecting the preservatives in each charge of the crop material as it is compressed in the bale forming chamber into a bale by the plunger of the baler. The nozzles are mounted in the face of the plunger and are opened for preservative injection only during the compression portion of the plunger cycle. While such a baler is reasonably effective in distributing the hay preservative and reducing the loss of preservative due to vaporization, improved uniformity of dispersion of the crop preservative throughout the crop material and improved reduction in the loss of preservatives are desirable. This is particularly true for at least three reasons when an ammonia hay preservative is used. First, loss of ammonia costs both for purchase of the ammonia itself and for wasted effort and possible local areas of spoilage. Secondly, ammonia is an irritant to eyes, nose and lungs, and excessive escape of ammonia during a hay baling operation may be offensive to someone nearby and downwind. Third, the absorption of ammonia into a plant such as alfalfa is much higher at temperatures below the ambient normally encountered in a hay baling operation. Therefore, it is desirable that the ammonia be retained as a liquid in the nozzle and that the evaporation and rapid cooling occur immediately upon expulsion to promote the absorption of it into the crop material.